The Internet is a general purpose, public computer network which allows millions of computers all over the world, hooked into the Internet, to communicate and exchange digital data with other computers also coupled to the Internet. Once a computer is coupled to the Internet, a wide variety of options become available. Some of the myriad functions possible over the Internet include sending and receiving electronic mail (e-mail) messages, browsing different web sites, downloading and/or uploading files, etc. In the past, activities over the Internet were limited due to the relatively slow connection speeds of dial-up modems over conventional telephone lines.
However, as new technologies emerge, the speed at which one can connect onto the Internet is ever increasing. Now, users on the Internet have the bandwidth to participate in live discussions in chat rooms, play games in real-time, watch streaming video, listen to music, shop and trade on-line, etc. In the future, it is imagined that the bandwidth will be such that video-on-demand, HDTV, IP telephony, video teleconferencing, and other types of bandwidth intensive applications will soon be possible.
Indeed, telecommunications companies are now laying the foundation to dramatically increase the bandwidth of the Internet backbone. Significant upgrades are being made to the routing, networking, and cabling infrastructure to keep up with the explosion in Internet traffic. One approach by which bandwidth is being increased relates to fiber optics technology. By sending pulses of light through glass fibers no thicker than a human hair, vast amounts of digital data can be transmitted at extremely high speeds. And with the advent of dense wavelength division multiplexing, different wavelengths of light can be channeled over the same, single fiber strand, thereby increasing its capacity several fold.
However, there is a problem with distributing the bandwidth of this new fiber optic network to end users. Essentially, this next-generation information superhighway has no real, effective entrance or exit ramps. Presently, service providers are using traditional local area network (LAN) switches and routers manufactured by companies such as Cisco, Nortel, and Lucent to perform the function of packet routing. Digital data is packetized; when a packet is transmitted by a user, that packet is examined and routed to its destination according to its IP address contained within that packet.
Although this process is standard and well-accepted, it suffers from several drawbacks. Namely, packets are transmitted asynchronously and sent best effort through the Internet. Due to traffic congestion, network overhead, routing conditions, and other uncontrollable external factors, this process is highly unreliable and unpredictable. Basically, packets vie for available bandwidth and are routed according to a best-effort delivery model. As such, the reliability of traditional LAN switches and routers is limited. Consequently, it is virtually impossible to provide any kind of quality of service (QoS) using traditional LAN switches and routers. QoS refers to the guarantee of providing timely delivery of information, controlling bandwidth per user, and setting priorities for select traffic. For real-time applications such as video on demand, HDTV, voice communications, etc., dropped packets or late-arriving packets can seriously disrupt or even destroy performance. And for many Internet Service Providers (ISP's), Applications Service Providers (ASP's), web sites/portals, and businesses, it is of paramount importance that they have the ability to provide a certain minimum threshold bandwidth. For example, a e-commerce or business web site may lose critical revenue from lost sales due to customers not being able to access their site during peak hours.
Because QoS is so highly desired by users, there exists mechanisms which have been developed to provide QoS functionality. However, these mechanisms are all extremely expensive to implement. One mechanism is commonly referred to as T-carrier services (e.g., T1 line for carrying data at 1.544 Mbits/sec. and T3 line for carrying data at a much faster rate of 44.736 Mbits/sec.). These T1 and T3 lines are dedicated point-to-point data links leased out by the telephone companies. The telephone companies typically charge long distance rates (e.g., $1,500-$20,000 per month) for leasing out a plain old T1 line. Another commonly used mechanism for achieving QoS relates to Synchronous Optical Network (SONET). As with T-carrier services, SONET uses time division multiplexing (TDM) to assign individual channels to pre-determined time slots. With TDM, each channel is guaranteed its own specific time slot in which it can transmit its data. Although TDM enables QoS, it is costly to implement because both the transmitter and receiver must be synchronized at all times. The circuits and overhead associated with maintaining this precise synchronization is costly. Furthermore, TDM based networking technologies are highly inefficient in that if a user does not transmit data within his dedicated time slot, that time slot goes empty and is wasted. In other words, TDM employs a use-it-or-lose-it approach whereby unused bandwidth is totally wasted; unused bandwidth cannot be reallocated to a different user.
Although the Internet backbone is being substantially overhauled to substantially increase its bandwidth, there is no mechanism in place today for distributing this bandwidth to end users that is cost-efficient, effective and yet which also has the ability of providing rate control on a per-flow basis. The present invention provides a solution to this networking need.